Tracking the Bighorn

The thick chaparral of a remote region in the Sespe Wilderness, part of the Los Padres National Forest, in Ventura, California, has concealed a lost herd of desert bighorn sheep for more than five years. But now they’re out in the open.

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The desert bighorn sheep of the Sespe Wilderness in California had been given up for dead. But they have resurfaced.
Chuck Graham

The animals were long ago given up for dead by the California Department of Fish and Game (DFG). But recent reports filtering down from hikers and hunters of bighorn sightings (as many as 29 animals) in the Sespe had given the DFG hope. "It absolutely amazed us," says DFG biologist Steven Torres, who heads the bighorn program for the state. "We’re committed to the survival of the California desert bighorn." Although there are 3,000 desert bighorn sheep in California, this is the westernmost population.

Between 1985 and 1987, DFG personnel transplanted 37 desert bighorn by helicopter from the San Gabriel Mountains north of Los Angeles 60 miles west to the Sespe. Desert bighorns hadn’t roamed this rugged range in 100 years.

From the moment those 37 animals were released with telemetry collars around their muscular necks, problems arose. Severe windstorms scattered the herd away from their habitat, and there was heavy predation from mountain lions. "But we also found that the core area where we released the sheep didn’t have a burn history," says DFG biologist Jim Davis. In 1985, the chaparral was thick in the Sespe, and today it’s nearly impenetrable, unless you’re a bighorn sheep. "It’s a distinct possibility that we may have lost the original herd in the thick brush," says Davis.

To combat the problems of chaparral overgrowth and predation, the DFG and U.S. Forest Service will conduct several controlled burns. "Bighorn rely heavily on their keen vision," explains Davis. "Controlled fires will enhance their foraging habits and give them a better chance against predators."

Now with encouraging reports of bighorn in the Sespe, the DFG is tracking the rediscovered herd in helicopters with substantial ground support. The agency has had surprising results. "We got curious after the reports," says Davis, who’s seen new lambs, yearlings and ewes within the herd. "We estimate that there are 60 to 70 animals, though the counting is tricky—if their timing isn’t accurate, they can overcount the same sheep."